South Carolina
Department of Health and Environmental Control
Total Maximum Daily Load Development for
Thompson Creek: Stations PD-246 and PD-247
Fecal Coliform Bacteria
August 26, 2003
Technical Report No. 02-04
Bureau of Water
Abstract
These TMDLs were developed for Thompson Creek (03040201-060), a small stream that is a tributary of the Pee Dee River. The watershed area affected by these TMDLs is located predominately in Chesterfield County, South Carolina (100 square miles), with several large tributary systems flowing south from Anson County, North Carolina (49.8 square miles).
The Clean Water Act requires that impaired water bodies be listed under Section 303(d) of the Act. Waters that are placed on the 303(d) list must have a TMDL determined for the pollutant of concern. Thompson Creek is impaired at water quality monitoring stations PD-246 and PD-247 near the Town of Chesterfield. Concentrations of fecal coliform bacteria exceeded the standard of 400 coliform forming units (cfu) per 100ml in more than ten percent of the samples acquired at these stations. Due to these fecal coliform bacteria excursions, recreational uses are not supported. The State of South Carolina has, therefore, placed Thompson Creek at PD-246 and PD-247 on the 303(d) list.
The part of Thompson Creek watershed that is included in this report is predominantly forest, with substantial cropland, and small amounts of pasture and wetlands. Less than 1 % of the land area is built-up. There is one permitted discharger in the watershed, the Town of Chesterfield’s wastewater treatment facility, which is just upstream of PD-247. The nonpoint sources that have been determined to be contributors to Thompson Creek
impairment include wildlife; grazing livestock and livestock depositing manure directly
into streams; land application of poultry litter; and malfunctioning septic systems.
HSPF was selected as the model to simulate existing conditions and load reduction allocations for the portion of the watershed upstream of PD-246. The application of this model to the project watershed area of Thompson Creek accounted for localized seasonal variations in hydrology, climatic conditions, and watershed land use activities. A load duration curve was generated to estimate loads for PD-247. The existing load and the TMDL load allocation (LA) for PD-247 were determined from the load duration curve.
The total maximum daily loads (TMDL) for these two creeks for fecal coliform bacteria were determined to be 5.56E+12 cts /30-days (PD-246) and 4.74E+14 cts /30-days (PD-247). These TMDL values would require reductions of 68 % and 82 % in the current loads to the creeks, respectively, to meet standards.
Table of Contents
Chapter Page #
1.0 Background 1
1.1 Watershed Description 1
1.2 Water Quality Standard 3
2.0 Water Quality Assessment 7
2.1 Spatial Variability 7
2.2 Seasonal Variability 8
2.3 Hydrologic Variability 8
3.0 Source Assessment 11
3.1 Point Sources 11
3.2 Nonpoint Sources 11
3.2.1 Wildlife 12
3.2.2 Cattle 13
3.2.3 Poultry Litter 14
3.2.4 Failing Septic Systems 14
3.2.5 Urban/Suburban Runoff 14
4.0 Modeling - PD-246 15
4.1 Approach and Model Segmentation 15
4.2 Meteorological Data 17
4.3 Hydrologic Simulation 18
4.4 Water Quality Simulation 22
4.5 Critical Conditions 22
5.0 Model Results – PD-246 24
5.1 Existing Conditions 26
5.2 Critical Conditions 26
5.3 Model Uncertainty 26
6.0 Load-Duration Curve – PD-247 27
7.0 TMDL 28
7.1 Waste Load Allocations 29
7.2 Load Allocations 29
7.3 Margin of Safety 29
7.4 TMDL 29
8.0 Implementation Planning Recommendations 30
9.0 References 30
Table of Contents (continued)
Appendix A Fecal Coliform Data 32
Appendix B Town of Chesterfield WWTP Data 34
Appendix C Hydrologic Parameters Used in the Black Creek/
Thompson Creek HSPF Models 38
Appendix D Public Notification 39
Appendix E Responsiveness Summary 40
List of Tables
Table Page #
1-1 Area and land use by sub-basins and counties. 6
1-2 Land use in the Jimmies and Thompson Creek watersheds (Thompson
Creek between PD-246 and PD-347 only). 6
2-1 Geometric Mean of Fecal Coliform Concentration v. Estimated Streamflow. 10
2-2 Results of Mann-Whitney Tests of Significant Differences in Fecal
Coliform Concentration 10
3-1 Fecal coliform loading rates from various sources. 13
3-2 Monthly Breakdown of Annual Poultry Litter Application 16
4-1 HSPF Modules Employed for the Thompson Creek Model. 17
4-2 Hydrologic parameters used in the Black Creek/Thompson Creek
HSPF Models. 18
4-3 Observed and Predicted Flow Volumes in Black Creek near McBee, SC. 19
5-1 Average Annual Coliform Loads to Thompson Creek at PD-246 24
5-2 Existing Loads to Thompson Creek for Thompson Creek at PD-246
and PD-247, calculated by different methods. 25
7-1 TMDLs for Thompson Creek at PD-246 and PD-247 (ct/30days). 29
List of Figures
Figure Page #
1-1 Map of the Thompson Creek watershed, Chesterfield County, SC and
Anson County, NC. 4
1-2 Map of the Jimmies Creek sub-basin of Thompson Creek watershed. 5
2-1 Fecal coliform concentrations v. time at the five 319 project stations. 8
2-2 Mean fecal coliform concentrations v. month in the Thompson Creek
study area. 8
2-3 Fecal coliform concentration v. estimated streamflow in the Thompson
Creek study area, 1995-2002. 9
3-1 Land use map of the Thompson Creek project area. 12
4-1 Sub-basin delineation of Thompson Creek for the HSPF model. 16
4-2 The Thompson Creek and Black Creek watersheds. 20
4-3 Observed and predicted mean daily streamflow at USGS gaging station
02130900 (Black Creek near McBee, SC). 21
4-4 Observed stage and predicted hourly streamflow in Thompson Creek
above highway S-13-243 (RCHRES 1). 21
4-5 Observed and predicted fecal coliform concentration in Thompson
Creek above highway S-13-243 (RCHRES 1). 23
5-1 Predicted fecal coliform concentration in Thompson Creek at PD-246
under low-flow, summer conditions. 25
5-2 Predicted fecal coliform concentrations in Thompson Creek at PD-246
under spring conditions. 26
6-1 Load-Duration Curve for Thompson Creek at PD-247. 28
7-1 30-day geometric mean values for Existing and TMDL conditions during
the critical period July 29 – August 27, 1999. 30
NOTICE
The TMDL for Thompson Creek at PD-246 was developed through a 319 grant. Thompson Creek is also impaired at PD-247, just down stream of PD-246. Rather than redoing the modeling work for this small additional area, the simpler Load-duration curve method was used for this additional station. Documentation for PD-247 has been added.
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1.0 BACKGROUND
Levels of fecal coliform bacteria can be elevated in water bodies as the result of both point and nonpoint sources of pollution. Section 303(d) of the Clean Water Act and EPA’s Water Quality Planning and Management Regulations (40 CFR Part 130) require states to develop total maximum daily loads (TMDLs) for water bodies that are not meeting designated uses under technology-based pollution controls. The TMDL process establishes the allowable loadings of pollutants or other quantifiable parameters for a water body based on the relationship between pollution sources and in-stream water quality conditions so that states can establish water quality-based controls to reduce pollution and restore and maintain the quality of water resources (USEPA, 1991).
The South Carolina Department of Health and Environmental Control (DHEC) has identified Thompson Creek in Chesterfield County as being impacted by fecal coliform bacteria at two locations, as reported on the State of South Carolina 1998, 2000, and 2002 303(d) lists of water quality impaired waters. The two monitoring stations are about 2 miles apart; PD-246 at S-13-243 and PD-247 at SC-9. It is assumed that water bodies possessing high concentrations of fecal coliform bacteria may also be contaminated by pathogens, or disease producing bacteria or viruses, which may exist in fecal material. Some waterborne diseases associated with fecal material include typhoid fever, viral and bacterial gastroenteritis, and hepatitis A. The presence of fecal contamination is, therefore, an indicator that a potential health risk exists for individuals exposed to this water.
1.1 Watershed Description
Thompson Creek is a small stream that rises near Pageland and flows through the Town of Chesterfield before it meets the Little Pee Dee River. The watershed is located in Chesterfield County, South Carolina and Anson County, North Carolina. This report is concerned with that part of the watershed upstream of SC-9, which has an area of 100 square miles. Several large tributaries, including Deadfall, Clay, Cedar, and Jimmies Creeks, flow south from Anson County (watershed area of 49.8 square miles).
Thompson Creek has two water quality monitoring stations: PD-246 at secondary road S-13-243 and PD-247 at SC-9. References to the project watershed indicate the part of the watershed draining to PD-246. Jimmies Creek and the small section of Thompson Creek between PD-246 and PD-247 will be discussed separately. The predominant soil types consist of an association of the Alpin-Tatum-Candor-Troup series, where the erodibility of the soil (K) averages 0.20; and the slope of the terrain averages 12 percent, ranging from 0 to 25 percent. The Natural Resources Conservation Service (NRCS) District Conservationist for Chesterfield County, South Carolina estimates that approximately 90 percent of the cropland acreage in the watershed project area is located on Highly Erodible Land (1999).
As portrayed in the Multi-Resolution Land Characteristics (MRLC) consortium’s National Land Cover Data, land use in the Thompson Creek watershed project area (Table 1-1) is predominately forest (74.7 percent); the remaining being cropland, (18.7 percent), pasture (6.1 percent), and developed (0.6 percent). The eight sub-basins in the project watershed area include:
Ø Lower Thompson Creek main-stem (18.7 square miles);
Ø Middle Thompson Creek main-stem (12.4 square miles);
Ø Upper Thompson Creek main-stem (8.1 square miles);
Ø Deep Creek (36.2 square miles);
Ø Cedar Creek (7.4 square miles);
Ø Deadfall Creek (30.2 square miles);
Ø Clay Creek (12.3 square miles); and
Ø Stone House Creek (8.0 square miles).
The following sub-watershed was not part of the 319 project and will be discussed separately:
Ø Jimmies Creek (13.1 square miles).
Table 1-1 shows that the most concentrated agricultural land use activities occur in two of the smaller Sub-basins: Cedar Creek (42.7 percent) and the Upper Thompson Creek main-stem (45.8 percent). Conversely, Deadfall Creek is the second largest Sub-basin, but contains the lowest concentration of agricultural land uses (7.9 percent). Agricultural land use information pertinent to fecal coliform bacteria loading in the Thompson Creek watershed project area provided by the NRCS field office personnel in May of 1999 included the following:
Chesterfield County, South Carolina
Ø Approximately 6,000 acres of active cropland; of which 3,500 acres utilize poultry
litter as a main source of fertilization;
Ø Approximately 4,000 acres of pasture; of which 1,500 acres utilize poultry litter as
a main source of fertilization;
Ø Nine poultry houses producing 3,500 tons of litter annually. Eight of the houses
are concentrated in the Stone House Creek Sub-basin. Additional quantities of poultry litter are trucked in from North Carolina. Most litter is stockpiled prior to application, and the majority of poultry litter is over applied.
Anson County, North Carolina
Ø Approximately 5,700 acres of active cropland, much of which is receiving poultry
litter;
Ø Approximately 1,350 acres of pasture and hay land;
Ø Two large swine operations (one of which possesses 880 animals) and two
nursery operations (possessing a total of 4,400 swine) are active.
Ø Boiler and turkey operations possessing a total of approximately 400,000 and
44,000 birds, respectively.
The watershed for Jimmies Creek is largely forested, but is 23 % in agricultural land use and 12.5 % in wetlands (Table 1-2). Approximately 31 % of the watershed is in Anson County, North Carolina.
There are no permitted discharge facilities in the project watershed area or the area upstream of PD-246. The Town of Chesterfield’s wastewater treatment facility is located downstream of Jimmies Creek and just upstream of monitoring station, PD-247. It is estimated that approximately 300 to 1,000 septic systems are currently in use in the project watershed area. The Town of Chesterfield relies on Thompson Creek as a source of public drinking.
1.2 Water Quality Standard
The impaired stream, Thompson Creek above S-13-243, is designated as Class Freshwater. Waters of this class are described as follows:
Freshwaters suitable for primary and secondary contact recreation and as a source for drinking water supply after conventional treatment in accordance with the requirements of the Department. Suitable for fishing and the survival and propagation of a balanced indigenous aquatic community of fauna and flora. Suitable also for industrial and agricultural uses. (R.61-68).
The South Carolina standard for fecal coliform bacteria in Freshwater is:
Not to exceed a geometric mean of 200/100 ml, based on five consecutive samples during any 30-day period: nor shall more than 10 percent of the total samples during any 30-day period exceed 400/100 ml. (R.61-68).
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Figure 1-1. Map of the Thompson Creek watershed, Chesterfield County, SC and Anson County, NC.
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Figure 1-2. Map of the Jimmies Creek sub-basin of Thompson Creek watershed.
Table 1-1. Area and land use by sub-basins and counties.
Sub-Basin / Name / Area / Area in Anson County / Area in Chesterfield County / Area in Union County / Land Use (%)(acres) / (acres) / % / (acres) / % / (acres) / % / Forest / Pas- ture / Crop- land / Deve- loped
1 / Lower Thompson Creek / 11,944 / 1,114 / 9.3 / 10,830 / 90.7 / 0 / 0.0 / 65.4 / 7.0 / 25.3 / 2.3
2 / Middle Thompson Creek / 7,938 / 1,254 / 15.8 / 6,684 / 0.8 / 0 / 0.0 / 81.8 / 5.2 / 12.9 / 0.0
3 / Upper Thompson Creek / 5,168 / 0 / 0.0 / 5,168 / 1.0 / 0 / 0.0 / 53.3 / 6.5 / 39.3 / 0.9
4 / Deep Creek / 23,178 / 0 / 0.0 / 23,178 / 1.0 / 0 / 0.0 / 70.5 / 4.2 / 24.7 / 0.6
5 / Cedar Creek / 4,727 / 3,436 / 72.7 / 1,291 / 0.3 / 0 / 0.0 / 57.3 / 9.6 / 33.1 / 0.0
6 / Deadfall Creek / 19,357 / 19,234 / 99.4 / 123 / 0.0 / 0 / 0.0 / 92.1 / 3.1 / 4.8 / 0.0
7 / Clay Creek / 7,893 / 4,302 / 54.5 / 3,248 / 0.4 / 342 / 0.0 / 77.5 / 12.8 / 9.7 / 0.0
8 / House Creek / 5,099 / 0 / 0.0 / 5,081 / 1.0 / 17 / 0.0 / 71.5 / 10.6 / 17.6 / 0.2
All / Thompson Creek up- stream of S-13-243 / 85,304 / 29,340 / 34.4 / 55,603 / 0.7 / 359 / 0.0 / 74.7 / 6.1 / 18.7 / 0.6
Table 1-2. Land use in the Jimmies and Thompson Creek watersheds (Thompson Creek between PD-246 and PD-347 only).